Manufacturers risk turning girls off careers in science and maths by producing gender-specific toys, the Education Minister has warned.

Elizabeth Truss said that companies marketing chemistry sets exclusively at boys was the “antithesis of what we want to promote” in the state school system.

She called for parents to buy more Lego for their daughters to get them interested in engineering.

Mrs Truss also backed a campaign established to call for the abolition of gender segregation in toy departments, insisting girls should not be pushed into fashion over farming.

The comments were made following a decision by Marks & Spencer to pledge that its range of toys would be “gender neutral” by this spring after being flooded with complaints from the Let Toys Be Toys campaign.

· Renewed her backing for a longer 8am to 6pm school day, insisting the country had to move away from existing “Victorian”-style timetables;

· Ruled out proposals suggested by Ofsted to introduce new tests for seven and 14-year-olds in England;

· Called on schools to “pay top dollar” to get the best graduates into the classroom.

Speaking to The House magazine, Mrs Truss said the campaign to abolish gender segregation in toy shops was a “fantastic” cause.

“The idea that a chemistry set should be for boys is the antithesis of what we want to promote,” she said.

“But at the same time we need to make clear that science and maths aren’t just about engineering cars, they’re also about developing LinkedIn, developing cosmetics, marketing.

“All sorts of jobs require science and maths, whether it’s fashion or farming, whatever you might aspire to, these subjects are useful. So we need a bit of balance I think.”

But Mrs Truss refused to criticise the launch of “Lego Friends” – a new pink and purple product range aimed at girls which replaces the traditional building blocks with “mini-doll” characters.

“You’ve happened on a complete dilemma we face in promoting maths and science,” she said. “I’ve got two daughters and I’ve bought traditional Lego and Lego Friends.

“To some extent you’ve got to engage children in what they’re interested in. You can’t just present something that’s totally different. Otherwise the child will just go off and spend their pocket money on what they want.”

Mrs Truss was also asked about Educating Yorkshire, the reality TV show depicting life in a Dewsbury comprehensive.

The minister, who attended a state secondary in Leeds, said that recent comments by the head of Ofsted about the prevalence of low-level disruption in schools were “absolutely right”.

She said she spent a year in school in Canada where “learning was something that was good, that it was cool, being top of the class was cool”.

“I’m afraid that was never the case in Leeds, it was always something to be a bit embarrassed about and teachers wouldn’t make a big deal of big performance,” she said.

“I’m always wary of commenting on reality shows because they always take people at their worst moments... But I think in general in too many schools there still is an acceptance that it is okay to think learning isn’t cool. And that feeds into behaviour and discipline and sometimes it gets to ridiculous levels.”

In other comments, she said the country still had a “pretty Victorian school day”, adding that proposals to allow all schools to open for longer would help working parents and enable pupils to catch up with better-performing peers in mainland Europe.